My DT350i only has 15,000km and developed a small leak from the water pump weep hole, mostly apparent after rides. Upon opening the radiator cap the overflow hose was clogged with Stop Leak powder. The hose connection to the overflow tank is only 2-3mm in diameter, making it easy to clog and cause overpressure, forcing coolant out of any hole, including the weep hole.
Rinsed the hose and did a full flush, all fixed.
